1. Field of the Invention:
This invention relates, in general, to forming presses and, more specifically, to magnetic core forming apparatus.
2. Description of the Prior Art:
Various arrangements have been used according to the prior art to form wound circular cores into rectangular shapes for use in power distribution transformers. U.S. Pat. Nos. 2,972,804 and 2,973,494, both of which are assigned to the assignee of this invention, illustrate magnetic cores of the type which are generally formed into a rectangular shape.
In most magnetic core forming arrangements, force is usually applied to all four sides of the magnetic core by a press which moves dies against each of the four outer surfaces of the rectangular core. While such an arrangement is economical and highly desirable from a manufacturing standpoint, it is usually necessary to have a separate set of dies dimensioned for each particular size and shape of magnetic core which is to be formed. Thus, unless a significant number of magnetic cores are to be made which have the same dimensions, it usually would not be economical to construct a set of dies so that the cores could be formed on automated or automatic pressing machinery. Therefore, it is desirable, and it is an object of this invention, to provide apparatus and a method by which a circular wound magnetic core may be formed into a rectangular core without the need for a set of expensive dies, thereby permitting the formation of a desired core shape economically for low volume production runs.
Other prior art forming arrangements have used non-automatic procedures to provide the desired rectangular shape. Most of these arrangements have made use of a press, which roughly forms the core into the desired rectangular shape, and a plurality of clamps which are applied to the roughly shaped magnetic core to more exactly shape the core into the desired rectangular shape and to maintain this shape until the core has been annealed. Such arrangements require considerable handling of the magnetic core and are susceptible to providing cores in which adjacent sides thereof are not exactly perpendicular to each other. Therefore, it is also desirable, and it is another object of this invention, to provide core forming apparatus and a method in which a minimum of core handling is required and the possibility of "parallelogramming" of the core sides is greatly reduced.